The proposed research continues work on individual fertility decision-making, especially as influenced by family sex composition preferences. There are three primary goals: 1. refinement of measures of the degree of bias in subjective probabilities for sex of next birth (many people believe that such probabilities are conditional on existing family composition); 2. extension of the fertility decision-making model to the process of couples making joint decisions; 3. assessment of the relative importance of and subjective probabilities for several factors affecting individual's choices of birth-control methods.